The present invention relates to a method of manufacturing semiconductor devices with accurately formed sub-micron features. The present invention has particular applicability in manufacturing high density semiconductor devices with transistors comprising ultra-thin gate oxides.
As microminiaturization proceeds apace, it becomes necessary to reduce the dimensions of transistors and, hence, the thickness of the gate oxide layers. However, conventional practices of forming a gate oxide layer, typically on a substrate comprising monocrystalline silicon, comprise thermal annealing, which does not enable the formation of ultra-thin gate oxide layers having a thickness less than about 10 xc3x85 with reliability and uniformity. Conventional thermal oxidation techniques result in gate oxide layers having a thickness greater than 10 xc3x85, which is about 2.5 atomic layers, due to the inability to control the thermal budget during thermal annealing. Further, such thermally formed gate oxide layers are uneven and difficult to reproduce with any appreciable degree of consistency.
Accordingly, there exists a need for methodology enabling the fabrication of semiconductor devices comprising ultra-thin, uniform and reproducible gate oxide layers.
An advantage of the present invention is a method of manufacturing a semiconductor device having an ultra-thin, uniform and reproducible gate oxide layer.
Additional advantages and other features of the present invention will be set forth in the description which follows and in part will be apparent to those having ordinary skill in the art upon examination of the following or may be learned from the practice of the present invention. The advantages of the present invention may be realized and obtained as particularly pointed out in the appended claims.
According to the present invention, the foregoing and other advantages are achieved in part by a method of manufacturing a semiconductor device, the method comprising: exposing an upper surface of a substrate to a laser light beam in an atmosphere containing oxygen to form a gate oxide layer thereon having a thickness of 3 xc3x85 to 8 xc3x85; forming a gate electrode layer on the gate oxide layer, and patterning to form a gate electrode and gate oxide thereunder.
Embodiments of the present invention include exposing the upper surface of a monocrystalline silicon substrate to a pulsed laser light beam at a radiant fluence of 0.1 to 0.8 joules/cm2 for about 1 to 10 nanoseconds, thereby elevating the temperature of the upper surface of the substrate to 1,100xc2x0 C. to 1,250xc2x0 C. and forming a gate oxide layer having a thickness of 3 xc3x85 to 5 xc3x85.
Additional advantages of the present invention will be readily apparent to those skilled in the art from the following detailed description wherein the embodiments of the present invention are described simply by way of illustration of the best mode contemplated for carrying out the present invention. As will be realized, the present invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.